Metallica's Lars Ulrich joined the British rockers Royal Blood onstage last night (April 15) at Slim’s in San Francisco. The drummer joined the duo for "Out of the Black," the final song of the band’s set Check out the fan-filmed footage above.

It’s not the first time the guys in Royal Blood have spent time with Ulrich. According to Blabbermouth, following the band’s show in San Francisco last October, the Metallica drummer took the duo out to see the city sights including the famed house used in the Robin Williams 1993 comedy Mrs. Doubtfire.

Royal Blood squeezed a few shows in California in between their Coachella performances. The duo will perform at Ace of Spades in Sacramento, Calif., on Sunday, the night after they play their second of two Coachella shows. You can check out all their tour dates here.

Meanwhile, Metallica are still working on their new album, which Kirk Hammett recently said is “at the 25 percent point, maybe 30 percent point.” He added, “It’s hard to say, but I mean we are working on it and there are songs and we’re making plans to write more songs and record.” The album is the band's follow-up to 2008’s Death Magnetic.